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- #!/usr/bin/ruby
- # Least number k > primorial(n) such that omega(k) = n-1.
- # https://oeis.org/A292427
- # Known terms:
- # 7, 33, 220, 2340, 30090, 511290, 9708270, 223136760, 6470164470, 200575098570
- # New terms:
- # 7, 33, 220, 2340, 30090, 511290, 9708270, 223136760, 6470164470, 200575098570, 7420875422730, 304251077160030, 13082794956764610, 614890302617971380, 32589185235841244010, 1922761748060828845170, 117288389032450202376810, 7858321607905303633368270, 557940834161276557969147170
- # PARI/GP program:
- #`(
- a(n) = my(A=vecprod(primes(n)), B=2*A); (f(m, p, j) = my(r=oo); forprime(q=p, sqrtnint(B\m, j), my(v=m*q); while(v <= B, if(j==1, if(v>=A && v < r, r = v; B = v-1), if(v*(q+1) <= B, r = min(r, f(v, q+1, j-1)))); v *= q)); r); f(1, 2, n-1); \\ ~~~~
- )
- for n in (2..100) {
- print(pn_primorial(n).next_omega_prime(n-1), ", ")
- }
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